ISSN:
1573-0662
Keywords:
stratosphere-troposphere exchange
;
tropopause folding
;
cross tropopause ozone transfer
;
vertical ozone profiles
;
potential vorticity
;
Q-vector divergence
;
7beryllium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract This paper gives a synthesis of three algorithms to detect the presenceof tropopause folds from vertical ozone/radio-sounding profiles and frommeteorological analysis. Also an algorithm to identify injection ofstratospheric air into the lower troposphere fromozone/7beryllium time series is presented. Differences in theresults obtained from the algorithms are observed and discussed with respectto the criteria for fold detection and input data used. Spatial gradients inthe obtained folding frequencies are made evident on a global scale from thealgorithm based on meteorological analysis (Q-vector/potential vorticity)and probably also on a regional European scale from algorithms both basedmeteorological analyses and on ozone/PTU soundings. The observed seasonalvariation of folding occurrence is rather flat except during summer whenalso some differences appear between the algorithms. By combining thefolding frequencies with literature estimates of the cross-tropopause ozonetransfer in single folding events, an average stratospheric ozone influxinto the troposphere of 5.7 ± 1.3× 1010 mol.cm-2 s-1 is obtained for the Northern hemisphereand 12± 2.7× 1010 mol. cm-2s-1 for Western Europe. Potential additional contributions dueto other stratosphere-troposphere exchange processes than folds are not yetincluded in these estimates. Finally, the link between statistics fromozone/7beryllium data and folding statistics is brieflydiscussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005897314623
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